import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.List;

@WebServlet(name = "upServlet")
public class upServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          request.setCharacterEncoding("utf-8");
          response.setContentType("test/html;charset=utf-8");
          if (!ServletFileUpload.isMultipartContent(request)){
              return;
          }
        FileItemFactory factory = new DiskFileItemFactory();
          ServletFileUpload upload= new ServletFileUpload(factory);
          upload.setFileSizeMax(1024*1024*30);
          upload.setSizeMax(1024*1024*40);
          upload.setHeaderEncoding("utf-8");
          String path = getServletContext().getRealPath("./")+File.separator+"upload";
          File uploadDir= new File(path);
          if (!uploadDir.exists()){
              uploadDir.mkdirs();
          }
        try {
            List<FileItem>fileItems=upload.parseRequest(request);
            if (fileItems!=null&&fileItems.size()>0){
                for (FileItem fileItem : fileItems) {
                    String fileName=new File(fileItem.getName()).getName();
                    String filepath=path+File.separator+fileName;
                    File file= new File(path);
                    fileItem.write(file);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
      this.doPost(request,response);
    }
}
